Anti-downdraft chimney head



April 7, 1970 G. E. HELM ANTI-DOWNDRAFT CHIMNEY HEAD 3 Sheets-Sheet 1 Filed June 20, 1968 Fig.2

R. m w! mm H w 6 E1 5 I M A w m E w 9% 0 Y 6 .B M m Fig.4

April 7, 1970 G. E. HELM 3,504,616

ANT I-DOWNDRAFT CHIMNEY HEAD Filed June 20, 1968 3 Sheets-Sheet 2 Fig 3 /54 /2 Gabriel E. h'e/m INVENTOR.

Attorney:

April 7, 1970 G. E. HELM 3,504,615

ANTIDOWNDRAFT CHIMNEY HEAD Filed June 20, 1968 s Sheets-Sheet :3

Fig. 7

Chimney Gabriel E. Helm INVENTOR.

United States Patent 3,504,616 ANTI-DOWNDRAFT CHIMNEY HEAD Gabriel E. Helm, Box 112, Kneeland, Calif. 95549 Filed June 20, 1968, Ser. No. 738,602 Int. Cl. F231 17/02 US. C]. 98-68 7 Claims ABSTRACT OF THE DISCLOSURE A chimney head that prevents a downdraft entering a chimney regardless of the angle of the downdraft. The chimney head is pivotable and adaptable to normal conditions or lesser angle downdrafts. The head receives the exhaust from the chimney and the downdraft collecting openings to disperse the same.

The present invention relates to a chimney head that is attached to the top of the chimney or flue. It is specially adapted to handle downdrafts. Normally, where mountains, heavy trees, large growths or other obstructions interrupt the prevailing wind, the wind goes over these obstructions and approaches the ground at angles up to the vertical. Such downdrafts being cooler denser air, in addition to their downward force, drive the smoke and gases in a flue or chimney back down into the house. This, naturally, is an undesirable situation rendering the chimney or flue unusable until these conditions change.

The device utilizes a venturi-like chamber to collect drafts directed substantially vertically downward and discharge them from a nozzle in a generally upward direction across the chimney opening into an exhaust chamber that reinforces the updraft created in the chimney by warm air and gas convection.

It is therefore an object of this invention to provide a unique, simple, easy to construct, chimney head that will prevent downdraft.

A further object of this invention is to provide a chimney head that will produce updraft in a chimney or flue regardless of the direction or angle of the prevailing winds.

These together with other objects and advantages which will become subsequently apparent reside in the details of construction and operation as more fully hereinafter described and claimed, reference being had to the accompanying drawings forming a part hereof, wherein like numerals refer to like parts throughout, and in which:

FIGURE 1 is a perspective view of the subject inven tion installed on a chimney.

FIGURE 2 is a top plan view of the subject invention with a portion broken away for purposes of illustration.

FIGURE 3 is an enlarged sectional view taken substantially along line 33 of FIGURE 2.

FIGURE 4 is a sectional view taken substantially along the line 4-4 of FIGURE 3.

FIGURE 5 is an enlarged sectional view of a means of attaching the device to a chimney liner.

FIGURE 6 is a perspective view of another form of the device.

FIGURE 7 is a section view taken substantially along the line 7-7 of FIGURE 6.

FIGURE 8 is a top plan view of the unit of FIGURES 6 and 7.

The chimney head is designated generally by the numeral 10. It is shown situated on a chimney 11 including ice a flue or chimney liner 12. The chimney head 10 includes an annular base or cap 14 with a top surface 16 having an opening 18 therethrough and depending peripheral flange or side 20. The opening 18 is sized to correspond with the area of the chimney liner or flue opening 12. Attached to the top surface 16 in perpendicular relation thereto are two sides 22. The sides are spaced apart approximately the width of the chimney liner or flue opening to coincide with the opening 18. This provides maximum efliciency and does not restrict the area of the opening of the flue or chimney liner. Attached to one end of and extending between the sides 22 is end section 24. The end section 24 begins at the top edge of sides 22. and continues downward in an arcuate curve to tangential engagement with the top 16 in the area of 26 where it is attached thereto, and terminates above the top surface 16 at 28. The chimney head is closed by a top 30. The top has a perpendicular section 32 spaced from arcuate end section 24 thereby forming an opening 34. The top 30 has a horizontal portion 36 which extends from perpendicular section 32 to the ends of sides 22 remote from end 24 forming an exhaust collection chamber 37 which has an opening 38 defined by the arcuate ends 40 of sides 22, horizontal section 36 and the top surface 16 of the cap. Mounted between the sides 22 and connected to the top 30 is an arcuate closed section 42. The section 42 begins at the apex of sections 32 and 36 and extends generally downwardly toward arcuate end 24 along surface portion 44 which turns into a generally circular portion 46 which ends at 48, adjacent end 28 of arcuate end 24 thereby forming a nozzle 51 at one side of the opening 18. Section 42 then continues upwardly in a sweeping reverse curve 50 that terminates on portion 36 of top 30. Thus, arcuate end 24 and portions 44 and 46 of section 42 form a venturi-like chamber 52 so that drafts entering opening 34 are greatly accelerated through the chamber and expelled at nozzle 51 in a generally upward direction across opening 18 and along arcuate surface '50 in chamber 37. This upward flow across the opening 18 creates a partial vacuum in this area adjacent the chimney opening or flue. The nozzle discharge as well as gases from the chimney are collected in chamber .37 and exhausted through opening 38. The chamber 52 is provided with a drain as at 53 to allow collected rain or melted snow to drain out.

A wind vane 54 is provided on the top 30 whose function will be disclosed hereinafter. The chimney head 10 is rotatably mounted on the chimney by a bracket generally indicated at 56. The bracket has a tube 58 fixed in the center of the chimney liner or flue by eight radial arms 60 grouped in spaced groups of four, which are welded to the tube 58 at 62. The arms 60 have perpendicular feet 64 welded to the arms at 66. The feet have apertures adapted to receive screws so that the arms may be fixed to the chimney liner or flue. Welded to the top of tube 58 is support collar 68. Shaft extends through tube 58 in rotating relation thereto and is fixed to the head 10. The shaft 70 is fixed to the head 10 by longitudinal braces 72 which are welded to top surface 16 of cap 14 at 74 and 76. The braces 72 form a diameter and intersect the shaft 70 at 78 and are welded thereto. A bearing 80 is fixed to shaft 70 in spaced relation to braces 72 and bears against collar 68 thereby rotatably suspending the head 10 from the chimney liner or flue 12. The shaft 70 is rotatably retained in tube 58 by a suitable nut 71 threaded on the lower end of the shaft 70, The upper end of the shaft 70 extends through the top 30 and has a clamping nut threaded thereon to stabilize the head on the shaft. The openings 34 and 38 in the head 10 may be covered with screen, as indicated at 82 and 84 re spectively, to act as a spark guard and to prevent foreign material entering therein.

The operation of the chimney head then, is that warm gases and smoke rise up the chimney into the head 10 and out of the opening 38. If there are any prevailing winds, the wind vane 54 keeps the arcuate end 24 heading into the wind so that the wind accelerates as it pro ceeds along the sides 22 and creates a partial vacuum in the area of opening 38. This creates an updraft in the chimney and further increaces the efliciency thereof. If there are any downdrafts, which would normally drive the gases and smoke back down the chimney, they are received in opening 34 and ducted through the venturi-like chamber 52 which accelerates the wind and discharges it upwardly at nozzle 51 to the chamber 37 to exit the head 10 at opening 38 with the chimney gases. This upward discharge of the nozzle 51 in chamber 37 creates a partial vacuum in the area adjacent the chimney opening and further reinforces the updraft created in the chimney. Thus it can be seen that downdrafts which normally render a chimney unusable until the conditions cease, are not only prevented from entering the chimney, but are turned into a beneficial force or updraft. It can thus be seen that in an area of prevailing downdrafts, the invention becomes extremely useful and economical. Further, the device also utilizes normal horizontal breezes to rein force updrafts in the chimney.

The modification of the device shown in FIGURES 6 through 8 is desirable where a chimney is under construc tion and space can be provided therein to conceal much of the device or where a minimum of the device is to be exposed to view for esthetic or other reasons In this embodiment two venturi-like chambers 152 are recessed within the chimney, shown in phantom lines. The drains 153 are provided in the chambers and exit outside the chimney wall. The chambers are fixed to and discharged in a chimney or flue extension 120 at upwardly directed nozzles 151.

Fixed in the center of the extension 120 by radial arms 160 is a tube 158 with a collar 168 fixed to the top of the tube. This central tube and support is analogous to the central bracket 56 of the prior embodiment. Rotatably received in the tube 158 is shaft 170, which forms a rotatable mounting for a head 110 which corresponds generally to the head 10. The head 110 has side walls 122 which have a forward arcuate end 149. The arcuate surface 150 forms the front wall of the exhaust collecting chamber 137 and the front wall of the head. The arcuate front surface will generate less of a load on the shaft 170 during high winds. The head 110 is fixed to shaft 170 at the top surface thereof and at the lower end by braces 172 fixed to the walls of the head 110 and intersecting in the center of shaft 170 where they are fixedly attached. A hearing 180 is fixed to shaft 170 below the braces 172 and bears against the collar 168 thereby rotatably suspending the head therefrom. As illustrated, the head 110 overlies the extension 120 so that all the upward drafts will impinge on curved surface 150 of exhaust collecting chamber 137 in the head and exit through opening 138. The wind vane 154 is provided on the top of the head 110 to orient the head into the wind and openings 138 at the downwind side. From this it can be seen that the operation is essentially the same as the prior modification. Regular warm gas and smoke convection will go through the extension 120, impinge on surface 150 of exhaust collecting chamber 137 and exit through opening 138. If there are any prevailing breezes the wind vane will point the head 110 into the wind so that the wind will accelerate along the sides 122 and create a partial vacuum in the area of opening 138 thereby reinforcing the air current up the chimney. In the event of downdraft, these are received in the venturi-like chambers 152 and discharged upwardly into chimney of the extension which creates a partial vacuum at the chimney of the opening and further reinforce the flow out opening 138.

The foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described.

What is claimed as new is as follows:

1. A device for a chimney comprising: mounting means adapted to be fixed to a chimney, exhaust collection means mounted on said mounting means, said collection means having means adapted to exhaust the chimney, means communicating with said exhaust collection means to collect downdrafts and use them to aid the exhausting of the chimney, said exhaust collection means being rotatably mounted on said mounting means, the mounting means comprising a tube rigidly fixed in the center of the chimney with a shaft fixed to said exhaust collection means and rotatably received within said tube, said exhaust collection means having a horizontally facing discharge, said exhaust collection means having a wind vane attached thereon to point the means into the wind and orient the horizontal opening downwind, said chamber being mounted for rotation with said collection means, said collection means comprising a venturi-like chamber with an exhaust nozzle, said chamber having an upwardly extending opening, said nozzle discharging generally up wardly, the rotating collection means overlying the upwardly facing nozzle whereby the nozzle exhausts upwardly into the collection means, there being two of said chambers spaced on opposite sides of said collection means to insure that the downdrafts from any angle will be received in a chamber and directed upwardly into the collection means.

2. In combination with a chimney having an upstanding fiue passage therein opening upwardly through the upper end of the chimney, a chimney head structure defined by a hollow housing supported from said chimney above and comprising an upward extension of said fiue passage, said housing opening downwardly into the upper end of said flue passage and including an upper wall structure overlying and closing the upper end of said passage from above, said housing being open on at least one side for discharging smoke from the interior of said housing in a downwind direction and further including means defining a chamber including inlet and outlet ends, said inlet end opening upwardly on one side of the upper wall structure in an unobstructed manner for receiving vetrical downdrafts, therein from above and said chamber extending downwardly from said inlet end and including a necked down lower portion curving smoothly inwardly toward said one side of said passage and then curving upwardly and opening upwardly along said one side of said passage below said upper wall structure.

3. The combination of claim 2 wherein said chimney head structure includes means defining a second chamber, corresponding to the first mentioned chamber, whose inlet end opens upwardly on the other side of said upper wall structure and whose necked down lower portion curves smoothly inwardly toward said other side of said passage and then curves upwardly and opens into said other side of said passage below said upper wall structure in an upward direction, said outlet ends being disposed at elevations lower than the vertical center of said one open side of said housing.

4. The combination of claim 2 wherein one side of said housing comprises the side thereof opposite to said one side of said upperwall structure.

5. The combination of claim 3 wherein said housing includes means defining an arcuate surface extending upwardly from, facing toward and curving laterally toward said open side of said housing for directing accelerated downdraft air discharged from said outlet end toward said Open side of said housing.

6. In combination, a flue structure defining an upstanding flue passage terminating at its upper end in a horizontally facing outlet for discharging in a downwind direction, said flue structure including means defining a chamber including inlet and outlet ends, said inlet end opening upwardly on one side of said flue passage in an unobstructed manner for receiving vertical downdrafts therein from above and such chamber extending downwardly from said inlet end and including a necked down lower portion curving smoothly inwardly toward said one side of said flue passage and then curving upwardly and opening upwardly along said one side of said passage below said upper wall structure.

7. The combination of claim 2 wherein said chimney head structure is supported from the upper end of said chimney for rotation about a vertical axis and includes Wind vane means operable to swing said chimney head structure, in response to horizontal wind flow thereabout, to a position with said open side of said housing opening in a downwind direction.

References Cited UNITED STATES PATENTS 315,522 4/1885 Loveless 9878 317,294 5/1885 Carll 98-70 1,128,271 2/1915 Pothemont 9870 1,393,775 10/1921 Hanson 9870 MEYER PERLIN, Primary Examiner US. Cl. X.R. 9870, 78, 119 

